Modern computers employ various forms of storage systems for storing programs and data. For example, various forms of disc drive systems have been designed to operate under the control of a computer to record information and/or retrieve recorded information on one or more recording discs. Such disc drives include hard disc drives which employ recording discs that have magnetizable (hard) recording material, optical disc drives which employ recording discs that have optically readable recording material, magneto-optical (MO) disc drives which employ recording discs that have optically readable magnetizable recording material, or the like.
Conventional disc drive devices typically comprise a variety of components, including motors or actuators, electronics, recording or reading heads and one or more recording discs supported for relatively high speed rotation within a closed disc drive housing. For example, FIGS. 1 and 2 show generalized representation of portions of a conventional disc drive system, including a conventional data storage or recording disc 200 supported on a rotary spindle 210. A disc drive motor, generally represented at 212, is operatively coupled to the spindle 210, for rotation of the spindle and the disc supported thereon. A recording and/or reading head 220 is supported by an actuator arm structure 222 adjacent, and in close proximity to, the recording surface of the disc. To simplify the disclosure, FIG. 1 is shown with a single recording disc 200 having a single recording surface and a single head 220 and actuator arm 222. However, other conventional disc drive systems employ multiple discs, double-sided discs (discs with recording surfaces on both surfaces) and multiple heads and actuator arms.
In many modern disc drive systems, the actuator arm 222 forms a part of an actuator assembly that pivots about a pivot mechanism disposed in a medial portion thereof. A limited movement motor, such as a voice-coil motor (not shown), is coupled to the actuator assembly and is operated to selectively pivot the actuator arm, to selectively locate the head 220 along the radial dimension of the disc surface. In this manner, the head 220 may be located adjacent any recording position on the recording surface for recording or reading operations, as the disc 200 is rotated.
The motor 212 used for rotating the spindle 210 and disc (or stack of discs) 200 must be capable of providing relatively high speed disc rotation, sustained over a suitable period of time to allow retrieval or recordation of data on the disc(s). One suitable motor design, comprises a hydrodynamic motor structure. Other disc rotation motor designs are well known in the art and have been employed in a variety of conventional disc drive devices.
Due to the nature of various materials, coatings and components used in the manufacture or assembly of a disc drive device, organic contaminants such as oils, hydrocarbons and other contaminants, can adhere to the surfaces of such components, materials and coatings during manufacture. For example, surface chemical contaminants tend to accumulate on disc rotation motor components during manufacture and assembly, especially motor components that are designed to hold a volume of oil or other lubricating fluid, such as components used in hydrodynamic motors as referenced above.
If such chemical surface contaminants are not properly removed from the disc drive components prior to completion of assembly, the contaminants can evaporate or otherwise be expelled into the environment within the disc drive housing interior and can migrate to other components within the disc drive housing. These contaminants tend to settle on other components within the disc drive housing, such as the heads and disc recording surfaces, and can adversely affect operational performance of the device. For example, organic contaminant accumulations on the head and disc surfaces are believed to be a cause of head stiction, a condition in which the head adheres to the disc surfaces.
Indeed, surface chemical contamination has become a critical issue on the interior components of disc drives. Organic contaminants such as films of silicone oil, hydrocarbons, fatty acid esters and amides have been linked to reliability problems that have become more severe as areal density of data on the disc increases and head-disc separation decreases.
Accordingly, steps may be taken during the manufacture or assembly of the disc drive device to remove surface chemical contaminants for various components and subassemblies of the device. However, removing contaminant films from certain components and complex subassemblies has proven to be difficult, especially in the clean room environments typically used in disc drive assembly facilities, where use of solvents must be minimized. Previous attempts to address this problem involved strict environmental and process controls to avoid the accumulation of surface chemical contaminants. However, such strict controls can are difficult to monitor and maintain. Thus there is a need for processes, compatible with a clean room environment, that provide surfaces that are cleaner than those resulting from traditional solvent wiping or aqueous cleaning alone and that can clean delicate components during and after assembly.
Ozone (O.sub.3) has been used for removing organic contaminants from water and for surface stripping of resist films as part of a process for manufacturing semiconductor devices. Ozone is a potent oxidizing agent that converts (burns) organic materials into water vapor and carbon dioxide. Ozone can be generated by an electric arc, a plasma source, or by short wavelength (200 nm or less) UV light. UV light generation has proven to be especially effective because the UV acts to generate ozone, excite the organic contaminants to make them more reactive with ozone and oxygen and destroy excess ozone.